The present invention relates to a hidden sliding track assembly for drawer or the like and more specifically, to a ball sleeve for use in the inner sliding rail of a hidden sliding track assembly, which has a narrow thin wall portion on the middle of the top wall of the sleeve body thereof for easy installation, and recessed bearing portions for supporting balls in respective openings in the sleeve body.
A regular ball sleeve 6 for use in a hidden sliding track assembly (see FIG. 1) has a sleeve body 61 of substantially η-shaped cross section. The sleeve body has four longitudinal rows of openings 611 respectively arranged in four angles of the inside space. Balls 7 are respectively mounted in the openings 611 by means of the application of a special mold and a special machine. After installation of the balls 7 in the openings 611, the ball sleeve 6 is coupled to the inner sliding rail 8 and the outer sliding rail 9. This ball sleeve installation procedure is complicated. In order to prevent falling of balls 7 out of the openings 611 of the sleeve body 61, the sleeve body 61 must be coupled to inner sliding rail 8 and the outer sliding rail 9 step by step each time a limited number of balls 7 have been installed in the openings 611. Further, the mounting tools are expensive.
The present invention has been accomplished under the circumstances in view. It is therefore one object of the present invention to provide a ball sleeve for use in the inner sliding rail of a hidden sliding track assembly, which is easy to install. It is another object of the present invention to provide a ball sleeve for use in the inner sliding rail of a hidden sliding track assembly, which is inexpensive to manufacture.
According to one aspect of the present invention, the ball sleeve has a narrow thin wall portion longitudinally extended on the middle between the two ends of the top wall of the sleeve body thereof through which the user can expand the sleeve body for easy installation of balls in the openings and easy coupling of the ball sleeve to the inner sliding rail of a hidden sliding track. According to another aspect of the present invention, the sleeve body of the ball sleeve further has a plurality of recessed bearing portions respectively disposed at two sides of each opening for supporting the balls in the openings, keeping the balls rotatably in close contact between the inner sliding rail and outer sliding rail of the hidden sliding track assembly.